#include <iostream>
#include <string>

using namespace std;

void test01()
{
    string s="hello";
    cout<<s.length()<<endl;
    s[2]='*';
    cout<<s[2]<<endl;
    cout<<s<<endl;

}

void test07()
{
    string str="hello world";
    for (int i = 0; i < str.length(); ++i) {
        cout<<str[i]<<endl;
    }
}

int main()
{
    test07();
    //test01();
    return 0;
}


